the corral, and B- Corral after changes: with fences blocking the animal’s vision and elimination of puddles.
| Livestock Research for Rural Development 30 (8) 2018 | Guide for preparation of papers | LRRD Newsletter | Citation of this paper |
This experiment was conducted to investigate the use of serum lactate to evaluate the quality of cattle handlings. Blood cortisol and lactate levels in Nellore steers were compared when they were handled in both the traditional way and after the introduction of calm handling methods and simple corral modifications. People using traditional methods yelled, hit cattle, and used both dogs and electric prods. The corral modifications consisted of blocking the vision of the steers when the handler stands inside the animal’s flight zone, eliminating contrast of light and dark or shadows and puddles. During calm handling, the stockperson was asked to be calm and not allowed to scream or hit the animals. Electric cattle prods or dogs inside the corral were not allowed. A total of 382 Nellore steers aged 14 to 20 months from five different ranches were studied. In the first evaluation, the behavior of the animals was evaluated and blood samples were collected after traditional handling. After corral modification and the introduction of calm handling procedures, the same animals returned (6 days later) for a second assessment and blood collection from the jugular vein for serum cortisol determination. The animals were evaluated using visual scores. Entry behavior (EB) into the restraint device was evaluated by observing whether the steers walked, trotted, or ran. Chute temperament (CT) was assessed by determining whether the animal was very calm, calm, agitated, very agitated or struggling to escape. Exit speed (ES) was evaluated with scoring of walk, trot or run. After both corral and handling modifications, the animals exhibited lower EB (P < 0.01), CT (P < 0.01), and ES (P < 0.01). Serum cortisol (P < 0.01) and lactate (P = 0.03) were significantly lower after the improvements. Mean serum cortisol was 47.87 vs 32.49 mg/dL, and lactate was 37.08 vs 33.65 mg/dL before and after corral and handling modifications, respectively. Lactate levels and exit speed are strongly related. Both exit speed score and serum lactate may be good tools to evaluate the quality of handling.
Key words: cattle stress, handling welfare, exit velocity
Nellore cattle raised on extensive pastures that have little contact with humans are generally shy and show a fear reaction when handled in corrals. The stress caused by handling is related to many factors (Grignard et al 2001, Grandin 2016). There is a need to improve welfare during handling.
Several studies have shown that Zebu cattle are more nervous and shy than taurine breeds (Becker and Lobato 1997, Heamshaw and Morris 1984) and carcass losses are consequently greater, in both male and female cattle (Mendonça et al 2017). The challenges may be greater on large Zebu beef cattle farms.
The way the handler interacts with the animals will result in calm or agitated behavior because animals react to the positive or negative stimuli from people (Hansson and Lagerkvist 2014). Ellingsen et al (2014) conducted a study of 110 farms in Norway, where the same observer scored the handler’s attitude and reactions towards the animals. The authors concluded that the behavior and attitude of the handlers directly influenced the fear reactions of cattle. One recommendation to solve this problem of lack of contact is to acclimate the animals to well-trained handlers (Ellingsen et al 2014, Probst et al 2013). On the other hand, in places where the cattle population is large and few personnel work with the animals, any conditioning to calm down the animals is very difficult.
Probst et al (2013) conditioned cattle by gentle touching of the head and neck region five weeks before slaughter. The treatment improved the behavior of the animals, reducing avoidance distance and blood lactate concentration, but did not affect cortisol concentration at the time of slaughter. However, according to these authors, when handled on another farm, animals conditioned to good handling often exhibit worsening of their behavior because of changes in the way people work. This fact highlights the importance of proper employee training.
According to Simon et al (2016), the use of an electric prod increases the risk of the animals balking, falling in the chute or running when exiting the chute. Their use should be avoided. Petherick (2005) stated that, in large companies, the attitudes of both the breeder and the animal handler are important to ensure both good animal welfare and quality handling. Training of employees is important and techniques should be taught based on cattle behavior. This will help improve habits, beliefs and attitudes. The calm interaction between humans and animals is fundamental to establish high-quality handling. Nervous and fearful animals are often aggressive towards people, which lead handlers to believe that they should treat aggressive animals roughly. This causes accidents and losses to humans and animals. Handling should provide a calm and safe work environment, regardless of the agitated response of animals (Petherick 2005, Grandin 2016).
Tense, fearful and aggressive animals exhibit high plasma levels of cortisol (Grandin 2016). Stockman et al (2012) found elevated serum lactate levels in cattle at slaughter when the animals were more nervous or anxious. Boles et al (2015) and Williams et al (2016) used blood lactate as an indicator of steer temperament and they met a significant, but not high, correlation between exit velocity and blood lactate levels, showing that lactate is an important physiological measurement to identify agitated and calm steers.
Modifications of existing handling facilities and the use of calm practices reduce handling problems, such as balking during entry into the restraint device, and improve animal flow (Grandin 2012). Lima et al (2018) found that calm improved cattle handling reduced both cortisol levels and exit speed scores. The purpose of this study was to determine if there are relationships between lactate levels and behavioral measures.
The present study was conducted simultaneously with Lima et al (2018). Traditional cattle handling with yelling, dogs, and electric prods was compared with calm handling, in which yelling was not performed and dogs and electric prods were removed. In the calm treatment, simple corral modifications were also made to improve handling. Principle component analysis was used to determine relationships between lactate levels and behavioral measures.
The experimental procedures of this study were approved by the Ethics Committee of the Animal Science Institute of Sao Paulo State, Brazil (Protocol 192-14). The study was carried out simultaneously with data collection by Lima et al (2017), on five different cattle farms (ranches) located in Central Brazil between the cities of Goias city (15o 94’S and 50° 14’W) and Jussara (15o 87’S and 50o 83’W), in Goias State, Brazil (Ranches 1, 2, 3, 4, and 5). The climate is classified as tropical, with the rainy season occurring during late spring and summer (November to March) and the dry season, during autumn and winter (April to October). The data were collected during the sunny winter days, in all ranches. The mean air temperature ranged from 20oC to 26oC and relative humidity from 45% to 60%. The temperature humidity index (THI) ranged from 62 to 73.
A total of 382 Nellore steers (male and female) aged 14 to 20 months, with a live weight of 300 to 400 kg, were studied (Ranch 1: 82 steers, Ranch 2: 80 steers, Ranch 3: 107 steers, Ranch 4: 53 steers, and Ranch 5: 60 steers). Before and after the procedures, all animals were kept on palisade grass pastures (Brachiaria brizantha) with free access to natural shading, a water drinker, and mineral and vitamin mix supplement.
The data were collected in corrals surrounded by 1.8-meter high fences made of wood boards (spaced 15 cm apart) on all five ranches (Figure 1). These corrals have the following divisions: pen, crowd pen, chute, and squeeze chute to restrain the animals. All restraint devices were made of wood. All steers had been handled prior to the experiment, undergoing vaccinations, administration of anthelmintic, and weighing twice a year. On the ranches, the steers are moved from the pasture to the corral facilities by horse riders.
Similar to Lima et al (2018), two treatments were applied: “poor corral and traditional handling” and “modified corral and calm handling”. All experimental steers were individually evaluated twice during handling in the corrals. First, the animals were randomly submitted to the “poor corral and traditional handling” treatment, which consisted of handling the animals in the traditional way (use of dogs inside the corral electric goads, running with horses, and shouting, pushing and hitting the animals). After blood collection, the steers returned to the pasture and, six days later, were submitted to the “modified corral and handling” treatment. After the first treatment, all animals were not handled for six days.
|
| A- Corral before changes |
|
| B- Corral after changes |
| Figure 1.
Schematic drawing of the corral A- Corral before changes: with fences, the
animals see the handler, and puddles inside the corral, and B- Corral after changes: with fences blocking the animal’s vision and elimination of puddles. |
The modified corral and calm handling treatment consisted of changes made in the corrals to facilitate handling and training of caretakers to handle cattle quietly and calmly. The following change was made in the corrals: blocking the animal’s vision when the handler stands next to the squeeze chute inside the animal’s flight zone. A solid panel was installed, similar to the methods of Muller et al (2008) and Grandin (2012). Bright objects or objects with color contrast were eliminated. The puddles were filled with soil and disappeared (Figure 1). Shadows and darkness were eliminated in areas with contrasts of illumination by replacing ceramic with glass roof tiles or installing an electric lighting system (Photo 1).
 |
| Photo 1. Corral before changes with fences, the animals see the handler
inside the animal’s flight zone (A) and corral after changes with fences
blocking the animal’s vision (B). Corral before changes with puddles inside the corral (C) and after changes with elimination of puddles (D), corral before changes with shadows and darkness (E) and after changes by replacing some ceramic with glass roof tiles (F) |
After these changes had been made in the corral, a training session was held with the employees to explain the modifications of the corral and how to handle cattle in a calm and quiet manner. They were told to stop shouting, pushing, and hitting the cattle. Lessons about the flight zone were taught. Differences were explained between human and bovine eyes. How cattle perceive things and reflections that induce fear were also explained. In addition, the fear induced by dogs and electric prods was explained, as described by Grandin and Deesing (2008).
Dogs were kept far away from the corrals and the use of electric goads was not allowed. When necessary, the handlers used a flag to encourage the flow and walked slowly to move the animals, as described by Grandin and Deesing (2008).
Behavioral assessments and blood collection were conducted in the squeeze chute during the restraint of each animal. After the experimental procedure, all animals of the same livestock farm were returned together to the pasture.
The same trained observer recorded the individual behavior score of each steer in the squeeze chute and another trained person collected all blood samples on the five ranches. The scoring system used was adapted from previous studies (Voisinet et al 1997, MacKay et al 2013, Vetters et al 2013, Lima et al 2018) and included entry, chute, and exit scores.
Entry and exit scores (1 to 3) were defined as follows: (1) walk, a four-beat gait characterized by progression of the alternate lateral legs, i.e., each hoof takes off from and strikes the ground independently; (2) trot, a two-beat diagonal gait in which the legs move in diagonal pairs, but not quite simultaneously, and (3) run, a three-beat gait in which the front hooves strike the ground, one after the other in a fast manner, followed by the rear hooves.
The chute scores (1 to 5) obtained during blood collection were defined as: (1) very calm, when the animal remains calm, without movement of body or hooves; (2) calm, when the animal moves its head and body gently; (3) agitated, when the animal moves a lot, including movement of the hooves, and gently shakes the body; (4) very agitated, when the animal moves briskly, shaking the body and moving the hooves simultaneously, and (5) struggling to escape, in which the animal is panicky or infuriated and struggles all the time to escape from the restraint.
Blood samples were collected from the jugular vein in heparinized tubes and immediately placed on ice. Immediately after the corral work, the samples were centrifuged at 2100 g for 15 minutes at 4oC and plasma was stored at -20oC until the time of cortisol and lactate analysis. Cortisol concentration was measured with an ELISA kit (Monobind, Inc., Lake Forest, CA, USA). The intra- and inter-assay coefficients of variation were 4.8% and 6.1%, respectively. Lactate concentration was measured by an enzymatic method using a commercial ELISA kit.
Similar to Lima et al (2018), statistical analysis was performed with the gamma model using PROC GENMOD (Generalized Linear Models) of the SAS program (SAS® Institute, Inc., Cary, NC). The model included the effects of treatment (poor corral and handling versus changed corral and handling), sex and ranch, and the interaction between treatment and ranch. In this model, the treatment effect was considered fixed, while the effects of the date of sampling and steer were considered random. The effect of sex was removed from the analysis model because it was not significant.
The next statistical analyses were performed using RStudio (Version 1.0.143 - © 2009-2016, RStudio, Inc.). The differences between cortisol and lactate concentrations and entry, chute, and exit scores were calculated by subtracting the values measured during “modified corral and calm handling” by the values measured during “poor corral and traditional handling”. Also, Principal Components Analyses (PCA; R’s “princomp”, “factoextra”, and “nFactors” packages) was performed to investigate the multiple relationships among the differences between cortisol and lactate concentration and entry, chute, and exit scores. The probability level to significant association applied in the PCA comprised variables that presented high loading values (≥ 0.60 or ≤ -0.60) at dimensions with eigenvalues higher than 1, and variances higher than 20%. After that, a Tree Decision (R’s “FactoMineR”, “missMDA”, and “factoextra” packages; P > 0.05) was performed using the original values of the most powerful (high loading values) differences in PCA (lactate concentration and exit scores) to distinguish the animals submitted to the “modified corral and calm handling” and “poor corral and traditional handling” treatments.
Afterward, a Linear Regression (R’s “stats” packages; P > 0.05) was conducted using the original values of the most powerful (high loading values) differences in PCA, in which the lactate concentration was a dependent variable and the exit score, an independent variable.
The changes made in corral arrangement and animal handling had a significant impact on both the behavior and blood parameters of Nellore steers. Table 1 summarizes blood cortisol and lactate concentration of the cattle during handling in the corrals. The results showed a significant effect of calm handling (P < 0.05) on the variables studied, which improved. There were interactions between treatment and ranch for entry score (P = 0.01), chute score (P < 0.01), and exit score (P < 0.01) of the Nellore steers (Figure 2).
|
Table 1. Entry score, chute score, exit score, cortisol release, and lactate concentration of Nellore steers submitted to poor corral and handling and changed corral and handling |
|||||
|
Treatment |
p value |
||||
|
Poor corral |
Improved corral |
Treatment |
Ranch |
Interaction |
|
|
Cortisol (ng/mL) |
47.9a ± 1.36 |
32.5b ± 1.37 |
<0.01 |
<0.01 |
0. 16 |
|
Lactate (mg/dL) |
37.1a ± 1.43 |
33.6b ± 1.42 |
0.03 |
<0.01 |
0.22 |
|
Results are the mean ± standard error of the mean.
|
|||||
 |
| Entry score (ranch x treatment) |
 |
| Chute score (ranch x treatment) |
 |
| Exit score (ranch x treatment) |
| Figure 2.
Interaction between ranch and treatment for entry score, chute score and
exit score. Means followed by the same lowercase letter do not differ significantly (p > 0.05) for treatments on each ranch separately |
For entry score, there was no treatment effect only for Ranch 1 (Figure 2). Chute score was not affected by treatment only on Ranch 2, with values close to the treatment mean (2.06 ± 1.05). There was no influence of treatment on exit score on two ranches, including Ranch 3 (1.22 vs 1.24) with a lower score than the treatment mean (1.48 ± 0.67) and Ranch 5 (1.71 vs 1.63) with a higher score. On the other hand, an important difference in exit score was observed for Ranch 4 (2.21 vs 1.23).
No interaction between treatment and ranch was observed for cortisol or lactate concentration (Table 1), but there was an effect of ranch on both blood parameters. The cortisol and lactate concentrations obtained for each ranch are shown in Table 2. Higher cortisol concentrations were observed on Ranch 1, indicating that the animals on this farm were more nervous, although there was a decrease in cortisol after improved handling (76.3 vs 56.8 ng/mL). Lactate levels were also found to be higher on Ranch 1 when compared to the other ranches, despite a decrease in lactate after treatment (47.2 vs 36.8 mg/dL).
|
Table 2. Cortisol release and lactate concentration of Nellore steers on each ranch where the study was conducted |
||||||
|
Ranch 1 |
Ranch 2 |
Ranch 3 |
Ranch 4 |
Ranch 5 |
p value |
|
|
Cortisol (ng/mL) |
66.5a ± 2.01 |
34.6c ± 1.84 |
29.4c ± 1.58 |
30.4c ± 3.07 |
43.1b ± 2.55 |
<0.01 |
|
Lactate (mg/dL) |
41.9a ± 1.95 |
37.2b ± 1.78 |
26.6c ± 1.52 |
<0.01 |
||
|
Results are the mean ± standard error of the mean.
|
||||||
Using Principal Components Analyses, the first dimension of the PCA (Figure 3) explained 49.8% of the total variance (eigenvalue = 2.4) and showed positive associations among the difference of the lactate concentration (0.78), exit (0.76), entry (0.72), and chute (0.67) scores.
The second dimension explained 18.2% of the total variance (eigenvalue = 0.9) and only cortisol showed a high loading value (0.77). It showed a strong link between serum lactate and the exit score.
The Tree Decision (Figure 4) classified that the animals submitted to “modified corral and calm handling” presented an exit score higher than one (P < 0.001). When in comparison with the animals subjected to “poor corral and traditional handling”, the proportion of animals that walked (exit score=1) was 38%, and after the changes in handling and corral, the proportion of animals that walked, after processing, was near 60%.
Because of the strong relationship between serum lactate levels and the exit score, a regression was established. The Linear Regression (Figure 5) produced the relationship (R = 0.22; R2 = 0.22; p < 2.2-16).
 |
| Figure 3.
Projections of the loading values in the two dimensions of the Principal
Component Analysis performed with the difference values of the cortisol and lactate concentration and the entry, chute, and exit scores |
 |
| Figure 4.
Tree Decision showing the classification of the animals between “poor corral
and traditional handling” (Handling.1) and “modified corral and calm handling” (Handling.2), applying the exit score |
According to Hansson and Lagerkvist (2014), the main problem is that farmers and employees develop their cattle handling methods based on their own needs, and improvements in farm animal welfare will only occur if there is improvement in their own wellbeing. The authors concluded that the attitudes of the handlers were based on behaviors that were learned from persons who preceded the current ones on the same farm and that these behaviors are similar to those observed on other farms. Considering the results of our study, we agree with Hansson and Lagerkvist (2014) since the corrals and the handling methods adopted were closely similar on the various farms studied. The animals showed reactions due to fear and these reactions were interpreted by the handlers as bad behavior. The handlers punished the animals showing poor behavior, usually with aggressive attitudes, hitting them and screaming. In our opinion, the changes in behavior proposed during employee training, with explanations about the fear reactions of the animals and about the need to change the behavior of people, improved the quality of the work of the persons involved. Work became slower and calmer, thus being less tiring for the handlers and improving the flow of the animals inside the corral.
Tirloni et al (2013) studied the influence of low-stress handling on cow reactivity. In that experiment, 66 cows were handled in a calm manner and 60 cows were handled aggressively. The results showed a significant difference in reactivity score during restraint (from 1 to 5, where 1 = very calm and 5 = highly reactive) between groups, which was 1.62 in animals handled in a calm manner and 2.12 in those handled aggressively. These results are similar to those found in the present study.
Analyzing the interactions between farm and behavior score, only one farm did not exhibit improvement in entry score (Ranch 1), which was already low, but chute and exit scores improved. On Ranch 2, no improvement in chute score was observed, while Ranch 3 and Ranch 5 did not exhibit any improvement in exit score. This finding might be explained by the fact that cattle react differently because of the history of each farm. Nevertheless, in general, improvement in at least two of the three behaviors was observed on each farm.
Hoppe et al (2010) investigated 24 commercial beef cattle farms in Germany using scores similar to those employed in the present study. The authors found differences in chute score and exit score between breeds. The Limousin and Charolais breeds were more agitated, with mean chute scores of 2.95 and 2.78, and exit scores of 1.8 and 1.65, respectively. These scores are higher than those observed in the present study, even during handling prior to the changes, when the animals were more agitated and stressed. Angus and Hereford cattle were calmer, with chute scores of 2.50 and 2.05, respectively, values higher than those found in our study when the animals were more agitated. Schwartzkopf-Genswein et al (2012), while investigating evaluation techniques of cattle behavior during handling, reported a mean entry score of 1.25, reactivity score in the chute of 1.71, and exit score of 1.46. These authors studied 28 crossbred Angus steers, which are generally calm animals, and the results were similar to those obtained in the present study for animals handled after the corral modifications.In our study, the exit score was able to distinguish the kind of handling, being that scores higher than 1 happened more in “poor corral and traditional handling”. Further, this exit score may be useful as tool to measure the handling quality
Gallo and Huertas (2016) demonstrated failure in the training of personnel that work with cattle on South American farms, where people tend to use aggressive strategies for animal handling, such as hitting the animals and twisting their tail, among other actions that cause pain. The factors cited by Gallo and Huertas (2016) were observed during traditional handling and were completely banned when the improved corral and handling practices were adopted. The elimination of dogs and electric prods was an important change to reduce the fear of the animals during handling inside the corral.
Disanto et al (2014) identified the main stress factors in 10 slaughterhouses in Italy. At all plants, the animals saw the movement of the personnel, which caused balking and delays in work. Five slaughterhouses had illumination problems. Perceiving a person inside the flight zone is very stressful for cattle that are unfamiliar with people and are being handled (Grandin, 2016). In the present study, improved illumination and blocking the animal’s vision by closing the lateral sides of the fence so that the animals did not see the handlers inside the corral in areas close to the squeeze chute were important changes. These modifications resulted in a reduction of fear, improving animal behavior.
Andrade et al (2001) compared the reactions of Brahman cows that used a mask or not to block their vision during handling in the chute. The use of the mask was alternated over the days of the experiment. There was an increase in blood cortisol levels in cows wearing the mask, demonstrating that the use of a mask increased stress. On the other hand, cows using the mask exhibited a better behavior during entrance into the chute and restraint, showing that the animals were emotionally less reactive during the procedures when they couldn’t see the people close to them. The observation of behavioral improvement corroborates the present results, proving that not seeing people reduces fear. Moreover, if blocking vision does not touch the animal, i.e., it is a fixed part of the corral, it is possible to reduce stress, as demonstrated by the decrease in cortisol and lactate in the present study. Blood cortisol showed a low link with other variables (Figure 3), although serum lactate showed a strong relation with the exit score (Figure 3).
Woiwode et al (2016) studied handling methods in Hereford steers and concluded that aversive procedures increase entry and exit speeds in the chute, as well as inadequate restraint. Injuries and losses occur when the animal is not restrained correctly, including a reduction in weight gain. Similar to the present study, Titto et al (2010) also found a reduction in cortisol levels in feedlot Nellore steers, as well as in the reactivity score during restraint. Williams et al (2016) observed a significant association between the exit velocity of steers and lactate (Pearson correlation coefficient=0.591) but no significant correlation between exit velocity and cortisol, similar to the results of the present work. When the authors classified the exit speed in fast, medium, and slow, they obtained blood cortisol concentrations of 22.5, 17.4 and 16.9 ng/mL, respectively, lower than the values described in the present study.
In relation to serum lactate, the authors classified the exit speed in fast, medium, and slow, and met serum lactate concentrations of 9.28 mmol/L (83.6 mg/dL) ; 4.76 mmol/L (42.9 mg/dL), and 3.86 mmol/L (34.7 mg/dL), respectively (Williams et al 2016). These values are higher than those reported in this work.
The lactate concentration and entry, chute, and exit scores were associated, while cortisol levels have multiple associations with other variables. Increases in cortisol were reported with fear (Forkman et al 2007), pain (Seesupa et al 2017), and stress (Dong et al 2018). However, lactate increases are related specifically with aerobic exercise in cattle (Birks et al 1991), which occurred during the tense moment when the animal was squeezed at chute for blood collection.
This study had financial support from Fapesp grant no: 2013/25355-6.
The authors declare that they have no conflicts of interest.
Andrade O, Orihuela A, Solano J and Galina C S 2001 Some effects of repeated handling and the use of a mask on stress responses in Zebu cattle during restraint. Applied Animal Behaviour Science, 71: 175–181
Becker B G and Lobato J F P 1997 Effect of gentle handling on the reactivity of zebu crossed calves to humans. Applied Animal Behaviour Science, 53: 219-224
Birks E K, Jones J H, Vandervort L J, Priest A K and Berry J D 1991 Plasma lactate kinetics during exercise. Equine Exercise Physiology, 3: 179-187
Boles J A, Kohlbecka K S, Meyers M C, Perz K A, Davis K C and Thomsona J M 2015 The use of blood lactate concentration as an indicator of temperament and its impact on growth rate and tenderness of steaks from Simmental × Angus steers. Meat Science, 103: 68–74
Disanto C, Celano G, Varvara M, Fusiello N, Fransvea A, Bozzo G and Celano G V 2014 Stress factors during cattle slaughter. Italian Journal of Food Safety, 3: 1682 Doi: 10.4081/ijfs.2014.1682
Dong J, Qu Y, Li J, Cui L, Wang Y, Lin J and Wang H 2018 Cortisol inhibits NF-κB and MAPK pathways in LPS activated bovine endometrial epithelial cells. International Immunopharmacology, 56: 71-77
Ellingsen K, Colemanb G J, Lunda V and Mejdell C M 2014 Using qualitative behaviour assessment to explore the link between stockperson behaviour and dairy calf behaviour. Applied Animal Behaviour Science, 153: 10–17 doi.org/10.1016/j.applanim.2014.01.011
Forkman B, Boissy A, Meunier-Salaün M C, Canali E and Jones R B 2007 A critical review of fear tests used on cattle, pigs, sheep, poultry and horses. Physiology & Behavior, 92: 340-374.
Gallo C B and Huertas S M 2016 Main animal welfare problems in ruminant livestock during preslaughter operations: a South American view. Animal, 10: 357–364 Doi: https://doi.org/10.1017/S1751731115001597
Grandin T 2012 Auditing animal welfare and making practical improvements in beef-, pork- and sheep-slaughter plants. Animal Welfare, 21: 29-34. DOI: https://doi.org/10.7120/096272812X13353700593400
Grandin T 2016 Evaluation of the welfare of cattle housed in outdoor feedlot pens. Veterinary Animal Science, 1: 23-28. https://doi.org/10.1016/j.vas.2016.11.001
Grandin T and Deesing M 2008 Humane Livestock Handling, first ed. Storey Publishing, North Adms, Massachusetts.
Grignard L, Boivin X, Boissy A and Neindre P L 2001 Do beef cattle react consistently to different handling situations? Applied Animal Behaviour Science, 71: 263-276
Hansson H and Lagerkvist C J 2014 Defining and measuring farmers’ attitudes to farm animal welfare. Animal Welfare, 23: 47-56 doi.org/10.7120/09627286.23.1.047
Heamshaw H and Morris C A 1984 Genetic and environmental effects on a temperament score in beef cattle. Australian Journal of Agricultural Research, 35: 723-733
Hoppe S, Brandt H R, Konig S, Erhardt G and Gauly M 2010 Temperament traits of beef calves measured under field conditions and their relationships to performance. Journal of Animal Science, 88: 1982–1989
Lima M L P, Negrão J A, Paz C C P and Grandin T 2018 Minor corral changes and adoption of good handling practices can improve the behavior and reduce cortisol release in Nellore cows, Tropical Animal Health and Production, 50 (3): 525-530
MacKay J R D, Turner S P, Hyslop J, Deag J M and Haskell M J 2013 Short-term temperament tests in beef cattle relate to long-term measures of behavior recorded in the home pen. Journal of Animal Science, 91: 4917-4924
Mendonça F S, Vaz R Z, Vaz F N, Restle J, Gonçalves G B and Vara C C 2017 Breed and carcass characteristics on losses by bruises and meat ph in beef of steers and culling cows. Ciência Animal Brasileira, 18: 1-10 Doi: 10.1590/1089-6891v18e-45295
Muller R, Schwartzkopf-Genswein K S, Shah M A and Keyserlingk G 2008 Effect of neck injection and handler visibility on behavioral reactivity of beef steers. Journal of Animal Science, 86: 1215–1222
Petherick J C 2005 Animal welfare issues associated with extensive livestock production: The northern Australian beef cattle industry. Applied Animal Behaviour Science, 92: 211–234
Probst J K, Hillmann E, Leibera F, Kreuzer M and Neff A S 2013 Influence of gentle touching applied few weeks before slaughter on avoidance distance and slaughter stress in finishing cattle. Applied Animal Behaviour Science, 144: 14-21
R STUDIO TEAM 2016 RStudio: Integrated Development for R. RStudio, Inc., Boston, MA. URL http://www.rstudio.com/, 2016.
Schwartzkopf-Genswein K S, Shah M A, Church J S, Haley D B, Janzen K, Truong G, Atkins R P and Crowe T J 2012 A comparison of commonly used and novel electronic techniques for evaluating cattle temperament. Canadian Journal Animal Science, 92: 21-31 doi.org/10.4141/cjas2011-040
Seesupa S, Wachirapakorn C and Aiumlamai S 2017 Effects of induced subacute ruminal acidosis and laminitis on lipopolysaccharide binding protein, cortisol and progesterone levels in dairy heifers. The Thai Journal of Veterinary Medicine, 47: 501-511
Simon G E, Hoar B R and Ticker C B 2016 Assessing cow-calf welfare. Part 2: Risk factors for beef cow health and behavior and stockperson handling. Journal of Animal Science, 94: 3488-3500
Stockman A A, McGilchrist P, Collins T, Barnes A L, Miller D, Wickham S L, Greenwood P L, Cafe L M, Blache D, Wemelsfelder F and Fleming P A 2012 Qualitative Behavioural Assessment of Angus steers during pre-slaughter handling and relationship with temperament and physiological responses. Applied Animal Behaviour Science, 142: 125-133.
Tirloni R R, Rocha F A and Lourenço Martins L R 2013 Influence of low-stress handling on reactivity score and pregnancy rate during fixed-time artificial insemination in Nellore cows. Revista Brasileira de Zootecnia, 42: 471-474 doi.org/10.1590/S1516-35982013000700002
Titto E A L, Titto C G, Gatto E G, Noronha C M S, Mourão G B, Nogueira Filho J C M and Pereira A M F 2010 Reactivity of Nellore steers in two feedlot housing systems and its relationship with plasmatic cortisol. Livestock Science, 129: 146-150
Vetters M D D, Engle T E, Ahola J K and Grandin T 2013 Comparison of flight speed and exit score as measurements of temperament in beef cattle. Journal of Animal Science, 91: 374-381
Voisinet B D, Grandin T, Tatum J D, O’Connor S F and Struthers J J 1997 Feedlot cattle with calm temperaments have higher average daily gains than cattle with excitable temperament. Journal of Animal Science, 75, 892-896
Williams A F, Boles J A, Herrygers M R, Berardinelli J G, Meyers M C and Thomson J M 2016 Relationship between current temperament measures and physiological responses to handling of feedlot cattle. College of Agriculture and Extension Research Report. 55-61. http: //msuextension.org/coa/documents/2016reports/ExitVelocityWilliams.pdf
Woiwode R, Grandin T, Kirch B and Paterson J 2016 Effects of initial handling practices on behavior and average daily gain of fed steers. International Journal Livestock Production, 7: 12-18 Doi: 10.5897/IJLP2015.0277
Received 6 May 2018; Accepted 23 July 2018; Published 1 August 2018